Since the April 2026 restructuring, reduced Section 232 rates turn on metal-level origin data that only the supplier can verify. Every entry of covered steel reports the country where the steel was melted and poured. Every entry of covered aluminum reports where the metal was smelted and cast. The same applies to copper. The lowest tier requires at least 85 percent US-origin metal by weight, a threshold lowered in June 2026 from 95 percent, and qualifying still depends entirely on supplier-verified data. Missing documentation means paying the full tariff, and an unsupported lower-rate claim creates exposure when CBP asks about reasonable care. The filing guidance is CSMS 68253075 from April 3, 2026, updated by CSMS 68855869 on June 5, and it directs filers to continue reporting melt and pour and smelt and cast countries following the instructions in CSMS 64348411, 64348288, and 65340246.
What CBP actually asks for on the entry
The entry summary carries the melt and pour or smelt and cast country as a data element, and the chapter 99 heading carries the rate. The two have to agree: a claim for a reduced rate under a heading that requires US metal content needs the mill certificate behind it, and the certificate needs to state the country of melt and pour or smelt and cast and the weight of that metal. CBP's FAQ states that ACE requires the reporting, and the proclamation tells CBP to write guidance on assessing US content, adding that if an importer misleads the government about that content, CBP shall impose penalties. The melt and pour paperwork is no longer a nice-to-have in the folder. It is the entry.
Basic steel mill products need a Commerce import license under 19 CFR Part 360 before the entry summary is filed. Copper is the exception that proves the rule: CBP announced it would say when it is ready to accept smelt and cast data for specific copper HTSUS codes, including 8544.42.10, 8544.42.20, 8544.42.90, and 8544.49.10, which means copper filers have to watch for the announcement rather than assume the data element is live.
Related reading on this site: TariffTrack HQ and Chapter 99 Lines Stack in a Set Order on the Entry Summary cover the neighbouring problems in more depth.
Why the supplier holds the answer
The country of melt and pour sits with the mill, and the mill sits two or three tiers up the supply chain from the importer. The direct supplier knows who assembled the product. They often do not know where the steel was melted, because they bought the steel from a distributor who bought it from a mill, and the chain of custody for the metal is not the same as the chain of custody for the finished good. The compliance team that needs the data has to ask for it explicitly, in the purchase order, before the goods ship, because asking after the entry is filed is asking for a document that may not exist.
The practical move is a supplier questionnaire with three fields: the country of melt and pour for steel, or smelt and cast for aluminum and copper, the weight of US-origin metal against total metal weight, and the mill certificate or smelter statement that supports both. Suppliers who cannot answer should be flagged, not dropped, because the flag is the reasonable care record: the importer asked, the supplier could not answer, and the entry was filed at the full rate. A full-rate entry with a documented question is defensible. A reduced-rate entry with no documentation is not.
The 85 percent test in the filing
The test is by weight of steel, aluminum, and copper, not by dollar value or by part count. A product whose metal is 85 percent US-melted steel by weight counts as entirely American metal, and the reduced rate follows. The threshold is the same for all three metals, and the calculation needs the weight breakdown from the mill, not an estimate from the invoice. An estimate is not evidence, and CBP can ask for the documentation behind the claim.
The reduced Annex I-C rates run only until December 31, 2027, and on January 1, 2028 the affected products revert to the full Proclamation 11021 rates. Build the sourcing decision with that date in mind: a supplier relationship that only works at the reduced rate has a dated shelf life, and the renegotiation should start before the rate expires, not after. The entry record should carry the calculation, the certificate, and the date, so that a review in 2027 can reconstruct why the rate was claimed.
Frequently asked questions
What does CBP require for Section 232 steel entries?
Every entry of covered steel reports the country where the steel was melted and poured, and every entry of covered aluminum reports where the metal was smelted and cast. Basic steel mill products also need a Commerce import license under 19 CFR Part 360 before the entry summary is filed.
What is the 85 percent test?
A product's metal counts as entirely US-melted steel or US-smelted aluminum or copper if that metal accounts for at least 85 percent of the weight of the metal in the product. The test is by weight, not by dollar value or part count.
Why does the supplier hold the melt and pour answer?
Because the country of melt and pour sits with the mill, two or three tiers up the supply chain. The direct supplier knows who assembled the product but often does not know where the steel was melted, so the importer has to ask for it explicitly, in the purchase order, before the goods ship.
What happens if the documentation is missing?
Missing documentation means paying the full tariff. An unsupported lower-rate claim creates exposure when CBP asks about reasonable care, and the proclamation states that CBP shall impose penalties if an importer misleads the government about US content.